Identification document including embedded data

ABSTRACT

The present invention provides methods and systems to authenticate identification documents. In a first implementation, an identification document includes a photograph and a digital watermark. The digital watermark carries first facial recognition data corresponding to a face depicted in the photograph. Optical scan data representing the photograph is received, and a second facial recognition data is derived. The first facial recognition data is recovered from the digital watermark, and is compared with the second facial recognition data.

RELATED APPLICATION DATA

The present application is a continuation of U.S. patent applicationSer. No. 10/094,593 (published as US 2002-0170966 A1), filed Mar. 6,2002, which claims the benefit of U.S. Provisional Patent ApplicationNo. 60/356,881.

The present application is also related to assignee's U.S. patentapplication Ser. No. 09/452,021, which is a continuation-in-part ofapplication Ser. No. 09/130,624 (now U.S. Pat. No. 6,324,573). The Ser.No. 09/130,624 application is a continuation of U.S. patent applicationSer. No. 08/508,083 (now U.S. Pat. No. 5,841,978). This application isalso related to the following U.S. patent application Ser. Nos.09/292,569, 09/314,648, 09/343,104, 09/452,023, 09/452,022, 09/571,422and 10/027,783. The technology disclosed in this application canadvantageously be used in the methods and systems disclosed in theforegoing patent and applications.

Each of the above-mentioned patent documents is herein incorporated byreference.

TECHNICAL FIELD

The invention relates to digital watermarking and the cooperation ofdigital watermarking with other machine-readable codes such as barcodes.

BACKGROUND AND SUMMARY

There are a variety of standard ways to encode information in amachine-readable code that is either affixed to or applied to thesurface of a tangible object. Perhaps the most widespread form ofmachine-readable code is the barcode, but there are many others. Otherforms of machine-readable identification include magnetic stripe,magnetic ink character recognition (MICR), optical character recognition(OCR), optical mark recognition (OMR), radio frequency identification(RF/ID) etc.

While these forms of machine-readable identification are widely used andeffective for many applications, they all have the disadvantage thatthey must occupy a dedicated portion of the physical object that theyreside on. For example, if one wishes to apply a barcode or magneticstripe to an object, the physical implementation of the code must occupysome portion of the object's surface apart from the other informationcontent on the object. For some applications, this limitation does notpose a problem. For many applications, however, the need to locate thecode on a dedicated portion of the object is a significant drawback. Onedrawback is that it requires the user to position the object so that theportion carrying the code can be read. Another drawback is that the codeis not aesthetically pleasing, and may detract from the overallappearance of the object. In addition, the placement of the code mayrequire an expensive and cumbersome manufacturing and applicationprocess.

Another characteristic of these forms of machine-readable identificationis that they are perceptible to the users of the object. Again, for manyapplications, this characteristic is not a concern, and may in fact be abenefit. In some cases, however, it is a disadvantage for the code to bevisually perceptible. As noted above, one drawback is that it detractsfrom the aesthetic appearance of the object. Another drawback is that itmay be more likely to be tampered with.

In some applications, however, it may be advantageous to combinebarcodes (or other machine-readable codes) and digital watermarks.Watermarks may be embedded in the information content (e.g., an image,photograph or graphics) or texture of an object's surface, and thus, donot require a separate, dedicated portion of the surface area. Whilesome forms of image watermarks are visible, many others may be embeddedsuch that they are virtually imperceptible to a user, yet readable by amachine.

In the following detailed description, watermarks and relatedmachine-readable coding techniques are used to embed data within theinformation content on object surfaces. These techniques are used incombination with standard machine-readable coding methods such as barcodes, magnetic stripes, etc. As such, the coding techniques extend tomany applications, such as linking documents together, identificationcard authentication, etc.

Further features and advantages will become even more apparent withreference to the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating an overview of a digitalwatermarking embedding process.

FIG. 2 is a flow diagram illustrating an overview of a digital watermarkdetecting process.

FIG. 3 is a flow diagram illustrating an overview of an authenticationprocess.

FIG. 4 is a flow diagram illustrating an alternative implementation ofan authentication process.

FIG. 5 is a flow diagram illustrating a barcode authentication process.

FIG. 6 is a flow diagram illustrating an authentication process thatcompares digital watermark information with another machine-readablecode.

DETAILED DESCRIPTION

Overview of a Digital Watermark System

The primary components of a watermarking system are an embedder and areader. The embedder encodes information into a watermark and applies itto an object, while the reader detects the watermark and decodes itsinformation content. FIG. 1 is a flow diagram illustrating an overviewof an embedding process. While advantageous to perform automatically,some of the steps may be performed manually, and may be implemented indistinct system components.

The process begins by obtaining an object message (100). In thiscontext, an object message is a general term referring to informationassociated with an object, including object identifiers, an index toother information or instructions, and machine instructions. Forexample, the message may be a product identifier such as a UniversalProduct Code (UPC). Or the message may include information that is alsoencoded on the object in other machine-readable code formats such as ina barcode. For many applications, it is advantageous to leverage anexisting object messaging scheme such as a UPC symbology, a magneticstripe coding format, or some other extrinsic standard. However, it isalso possible to develop a customized messaging scheme tailored to meetthe demands of a particular application.

Next, the object message is converted into an object reference (102).The objective of this stage is to place the message in a data formatsuitable for transforming into a watermark signal. In some instances,the message may already be in a data format that can be directlyconverted to a watermark information signal (e.g., a binary number). Inthis case, there is no need to transform the object message into adifferent data format. In other instances, the object message may beexpressed as a numeric or alphanumeric string representing some codedformat. In this case, the embedding process decodes and transforms themessage into a form suitable for conversion to a watermark. This processmay involve, for example, decoding and mapping each character or groupsof adjacent characters into a binary number.

Next, the object reference is transformed into a watermark signal (104).The watermark signal defines how to manipulate the information contentconveyed on the object's surface so as to place a watermark on theobject. The specific details of this process depend on the nature of thewatermark.

The watermark may be embedded in the information content of a digitalimage, for example. A digital image is comprised of a two or moredimensional array of image samples. In this case, the image samplevalues are manipulated to embed the watermark signal in the image. Theterm “image sample” refers generally to a discrete value in the imagearray. The image sample constitutes a value in any one of severaldomains, such as a spatial or frequency domain. In any given domain,image content may be represented in a variety of standard or customformats or color spaces. A color space may have one or more dimensions.For example, a monochrome image typically has a single dimensionrepresenting a gray-scale value, while a color image typically has threedimensions, e.g., RGB (Red, Green, and Blue); or YUV (Luminance, and twoChrominance components).

While a digital watermark is typically applied to digital content, itmay be implemented so as to remain with the content even throughtransformations to and from the analog domain. In addition to images, itapplies to a variety of different media types, including audio andvideo.

The assignee's watermarking technology is reflected in U.S. patentapplication Ser. No. 09/503,881 (now U.S. Pat. No. 6,614,914), U.S. Pat.No. 5,862,260 and laid-open PCT Application WO97/43736 (corresponding toU.S. patent application Ser. No. 08/746,613). Of course, other digitalwatermarking embedding techniques can be employed with our presentinvention, particular when other techniques provide a digital watermarkwith information carrying capacity.

Another way to encode additional information in an image is in the formof a data glyph. An implementation of data glyphs is described in U.S.Pat. No. 5,315,098. Related visible watermarking work is illustrated inU.S. Pat. Nos. 5,706,364, 5,689,620, 5,684,885, 5,680,223, 5,668,636,5,640,647 and 5,594,809.

Alternatively, the watermark may be embedded in line graphics or text byvarying the position of lines or characters in a manner that encodes theobject reference.

In summary, watermarking can be applied to myriad forms of information.These include imagery (including video) and audio—whether represented indigital form (e.g., an image comprised of pixels, digital video, etc.),or in an analog representation (e.g., non-sampled music, printedimagery, banknotes, etc.). Watermarking can be applied to digitalcontent (e.g. imagery, audio) either before or after compression (MPEG2,MPEG4, MP3). Watermarking can also be used in various “description” or“synthesis” language representations of content, such as StructuredAudio, Csound, NetSound, SNHC Audio and the like (c.f.http://sound.media.mit.edu/mpeg4/) by specifying synthesis commands thatgenerate watermark data as well as the intended audio signal.

Watermarking can also be applied to ordinary media, whether or not itconveys information. Examples include paper, plastics, laminates,product labels and packaging, paper/film emulsions, etc. A watermark canembed a single bit of information, or any number of bits.

The physical manifestation of watermarked information most commonlytakes the form of altered signal values, such as slightly changed pixelvalues, picture luminance, picture colors, DCT coefficients,instantaneous audio amplitudes, etc. However, a watermark can also bemanifested in other ways, such as changes in the surface microtopologyof a medium, localized chemical changes (e.g. in photographicemulsions), localized variations in optical density, localized changesin luminescence, etc. The surface texture of an object may be altered tocreate a watermark pattern. This may be accomplished by manufacturing anobject in a manner that creates a textured surface or by applyingmaterial to the surface (e.g., an invisible film or ink) in a subsequentprocess. Watermarks can also be optically implemented in holograms andconventional paper watermarks.

When determining how to implement this aspect of the embedder, there area number of design objectives to consider. One objective to consider isthe degree to which the watermark is imperceptible upon ordinaryinspection. As the watermark becomes less perceptible, it may alsobecome more difficult to detect and read accurately. Another objectiveis the quantity of information that one wishes to embed in thewatermark. As the quantity of information increases, the watermark willneed to support larger object references. Yet another objective issecurity. In some applications, it is desirable to employ an objectreference scheme that makes the object references more difficult todecipher or remove from the objects.

Having created a watermark signal, the embedder creates the watermarkedobject (106). As referenced above, this process may involve printing orapplying a watermarked image to the surface of the object, or texturingthe surface of the object so as to impart the watermark to the object.

Once embedded in the object, the object reference serves as amachine-readable code that conveys information about the object, amachine instruction or instructions, or an index to information orinstructions. Any compatible reader may extract the object reference.FIG. 2 is a flow diagram illustrating an overview of the readingprocess. Typically, the reader system incorporates a combination ofhardware and software elements. First, the reader scans the objectsurface to capture a digital representation of the surface (e.g., animage, or map of surface topology) (200). Next, the reader processes thesurface representation to detect whether a watermark is present (202).If so, the reader proceeds to read the watermark payload (204). In someimplementations, a separate detection process is not performed.

Bar Codes

Over the years, a number of standards organizations and private entitieshave formed symbology standards for bar codes. Some examples ofstandards bodies include the Uniform Code Council (UCC), EuropeanArticle Numbering (EAN, also referred to as International ArticleNumbering Association), Japanese Article Numbering (JAN), HealthIndustry Bar Coding Counsel (HIBC), Automotive Industry Action Group(AIAG), Logistics Application of Automated Marking and Reading Symbols(LOGMARS), Automatic Identification Manufacturers (AIM), AmericanNational Standards Institute (ANSI), and International StandardsOrganization (ISO).

The UCC is responsible for the ubiquitous bar code standard called theUniversal Product Code (UPC). AIM manages standards for industrialapplications and publishes standards called Uniform Symbology Standards(USS).

Some well know bar code schemes include UPC and UCC/EAN-128, Codabardeveloped by Pitney Bowes Corporation, I 2 of 5 and Code 128 developedby Computer Identics, Code 39 (or 3 of 9) developed by IntermecCorporation, and code 93.

Some bar codes, such as UPC, are fixed length, while others are variablelength. Some support only numbers, while others support alphanumericstrings (e.g., Code 39 supports full ASCII character set). Someincorporate error checking functionality.

While the bar codes listed above are generally one-dimensional in thatthey consist of a linear string of bars, bar codes may also betwo-dimensional. Two dimensional bar codes may be in a stacked form(e.g., a vertical stacking of one-dimensional codes), a matrix form, acircular form, or some other two-dimensional pattern. Some examples of2D barcodes include code 49, code 16k, Data Matrix developed by RVSI,Maxicode, QR code, micro PDF-417 and PDF-417. Of course, this is not anexhaustive list of 2-D barcodes. The present invention can be suitablyutilized with other barcode symbologies. All of the above bar codeschemes encode a relatively small amount of information and suchinformation (or a subset of such information) may be converted intowatermark signals using the method outlined in FIG. 1.

For more information on bar codes, see D. J. Collins, N. N. Whipple,Using Bar Code-Why It's Taking Over, (2d ed.) Data Capture Institute; R.C. Palmer, The Bar Code Book, (3^(rd) ed.) Helmers Publishing, Inc., andP. L. Grieco, M. W. Gozzo, C. J. Long, Behind Bars, Bar CodingPrinciples and Applications, PT Publications Inc., which are herebyincorporated by reference.

Applications

Interrelating Digital Watermarks and Barcodes

Digital watermarks can be used in connection with traditional barcodes.For example, a digital watermark can include information to verify,decrypt or decode the barcode, or vice versa. In one implementation, adigital watermark includes a payload carrying information related to thebarcode. For instance, the digital watermark may include a hash of thebarcode information or of a subset of the barcode information. Inanother implementation, the digital watermark includes a key to decryptor decode the barcode. Or the digital watermark payload and the barcodeinformation interrelate (e.g., match or mathematically coincide.).

Identification Cards

Now consider an identification card. An identification card can includea driver's license, passport, company identification, identificationdocument, membership card, national identification card, insurance card,etc., etc., etc. The identification card includes a barcode, e.g.,carrying at least variable information such as a cardholder's name,address, card number, and optionally, a photograph information,biometric information, etc., etc. The barcode can be printed on eitherside of the identification card. Most frequently, however, the barcodeis positioned on a backside of the card. The identification card willtypically include a photograph and printed information to identify thecardholder. The card can also include so-called fixed information. (Forexample, fixed information on a driver's license may identify the State,DMV information, or other information that is not personal with respectto the card's holder.).

The identification card includes a digital watermark embedded therein.The digital watermark includes a payload or other information bits.While the digital watermark can be embedded variously throughout thecard (e.g., in printed areas, background texture, photograph, etc.),embedding preferably occurs in at least the photograph.

In a first implementation, the watermark payload includes a hash of theinformation carried by the barcode. Most generally, a hash includes theresult of an algorithm that converts data into a lower number of bits.Examples of hashing algorithms include MD5, MD2, SHA, and SHA1, amongothers. A hash can also include a subset of the barcode's informationset. For instance, the barcode may include a cardholder's photograph,birth date, name and card number. A subset hash may then include asubset of this information, e.g., only the birth date and card number.

The interrelationship between the barcode and digital watermark are usedto verify the authenticity of the identification card. One verificationimplementation is described with reference to FIG. 3. A digitalwatermark is detected and decoded (step 10). The digital watermarkincludes a payload having verification information, such as a hash asdiscussed above. And the barcode is read and decoded in step 12. We notethat the order of steps 10 and 12 is not critical, unless either thedigital watermark or the barcode includes a key to decode or decrypt theother. The digital watermark data is compared with the barcodeinformation (step 14). The comparison may include recalculating a hashof the barcode information and comparing the recalculated hash against ahash carried by the digital watermark. Or if the digital watermark hashincludes a subset of the barcode information, the subset is comparedagainst the barcode information set. (For example, the subset hash mayinclude the cardholder's birth date and card number. This information iscompared against the barcode birth date and card number.). Or if thedigital watermark payload includes a key for decoding/decrypting thebarcode, the comparison step may include determining whether the barcodecan be successfully decoded/decrypted, or vice versa. In still anothercase, the digital watermark includes the full set of barcodeinformation, and not just a subset of such information. Still further acomparison may determine whether the watermark information coincideswith the barcode information.

The result of the comparison step 14 is used to determine whether thisdigital watermark and barcode information match or otherwise coincide(step 16). The term “match” is defined broadly herein to include anexact match and a predetermined relationship, such as a cryptographicrelationship, overlap of data sets or other predetermined relationship.The process preferably provides an indication of whether the card isauthentic (18) or not (20).

This authentication method is helpful in preventing counterfeiters orforgers. For example, suppose an identification card is embedded with afirst digital watermark. The identification card belongs to say 16-yearold Joan. The identification card further includes Joan's photograph anda barcode including at least Joan's variable information (name, sex,age, etc.). The first digital watermark includes a hash or otherinformation that corresponds in some manner to Joan's barcodeinformation. Joan decides that she wants to “up-grade” her age, bycutting and pasting her identification card photograph onto her 22-yearold sister, Molly's, identification card. Molly's identification cardalso includes a barcode with her variable information.

Joan pulls off a professional job replacing Molly's photo with her own.All seems fine for Joan until the verification process of FIG. 2 is usedto verify the identification card. Joan's first digital watermark hash(included in Joan's photograph) does not match Molly's barcodeinformation—confirming that the photograph does not belong to theidentification card. The counterfeit is justly determined.

A similar verification process can be carried out for watermarksembedded in regions other than a photograph.

In some counterfeiting scenarios, a photograph without a digitalwatermark is used to replace an original, digitally watermarkedphotograph. To handle this case, the authentication method of FIG. 3 maybe modified to include steps 10′ and 10 a to determine whether thedigital watermark is recovered or successfully read, e.g., prior to step14. If the digital watermark is not recovered the document is consideredfraudulent or at least not valid. Similar steps 12′ and 12 b areoptionally implemented to determine whether the barcode is decoded. Ouralternative implementation is shown in FIG. 4.

Another alternative implementation is shown in FIG. 5. In thisimplementation, we compare barcode information against informationprinted on or otherwise contained in or on the identification card. Thebarcode is decoded (step 12). As discussed above with respect to FIG. 4,step 12 a (not shown in FIG. 5) is optionally provided to ensure thatthe barcode is successfully recovered. Information contained on or inthe identification card is captured through, e.g., optical characterrecognition (OCR), manual input, magnetic stripe, data retrieved fromelectronic circuitry in the identification card (if provided), etc.(step 13). The captured information is compared with the barcodeinformation (step 14). The result of the comparison step 14 is used todetermine whether the captured text and barcode information match orotherwise coincide (step 16). The process preferably provides anindication of whether the card is authentic (18) or not (20). Thisimplementation helps detect a situation where Joan decides to also“cut-and-paste” her barcode onto Molly's ID card. Of course, this methodcan be combined with those shown in FIGS. 3 and 4. For example, themethod illustrated in FIG. 5 can be carried out between steps 12 and 14in FIG. 3 and/or between steps 12 a and 14 in FIG. 4.

In another implementation shown in FIG. 6, comparison data isalternatively captured instead of retrieving the comparison data from abarcode (step 30). For example, the comparison data is gathered viaoptical character recognition (OCR), a magnetic stripe, magnetic inkcharacter recognition (MICR), optical mark recognition (OMR), manualinput, or in a case where the identification card includes so-calledSmartcard or RFID circuitry, from electronically stored data. The FIG. 6implementation otherwise proceeds as discussed above with respect toFIG. 3. (We note that the FIG. 6 implementation can be modified toinclude the optional steps 10′ and 10 a as discussed with respect toFIG. 4.).

Watermark Reading Devices

There are many suitable computing devices that can be used with thepresent invention. One is a general-purpose computer including standardprocessing structure, an image capture device (e.g., a digital camera,optical sensor, etc.) and memory. The memory includes digital watermarkdetecting software instructions stored therein for execution on theprocessing structure (e.g., a CPU). The image capture device can betethered to the computer or can wirelessly communicate with thecomputer.

We have also found that conventional 2-D barcode readers can be modifiedto achieve digital watermark detection. Such barcode readers generallyinclude an imaging sensor such as a CMOS sensor or a CCD array. One suchsuitable imaging sensor is the OmniVision Technologies barcode camera.OmniVision is headquartered in Sunnyvale, Calif., 94085, USA. Seewww.ovt.com for even more information. Another suitable barcode readeris the Welch Allyn Dolphin product, which includes Intel's StrongArmprocessor and runs Windows CE. Symbol Technologies, Inc., which isheadquartered in Holtsville, N.Y., USA, develops other suitable barcodereaders. Examples of such include Symbol's VS4000 and P300IMG models.These readers include a progressive scan CCD with an optical resolutionof about 640×480 pixels×256 shades of gray. (Even more information aboutSymbol's readers can be obtained from Symbol Technologies or atwww.symbol.com/products/barcode_scanners).

Of course, there are many other known barcode readers that can besuitably interchanged with the present invention. We also anticipatethat barcode readers will continue to improve and advance. Suchimprovements are anticipated to be suitably interchangeable with thepresent invention.

A 2-D barcode reader is programmed with digital watermark detectingsoftware. The 2-D barcode reader captures an image of a document orobject that is embedded with a digital watermark. The digital watermarkdetecting software analyzes the captured image to decode the digitalwatermark. (We note that such digital watermark detecting software isreadily implemented in view of this and the incorporated by referencepatent documents.).

A 2-D barcode/digital watermark reader is an advantageously solutionsince it can read and decode both 2-D barcodes and digital watermarks. A2-D barcode reader can even be programmed to carry out theauthentication method of FIG. 3 and other document verification methods.

Such a 2-D barcode is also capable of capturing relatively high qualityimages. This advantageous feature can be combined with our digitalwatermarking techniques. For example, a 2-D bar code reader captures animage of a cardholder's face. Facial recognition software processes theimage to generate a hash. The same 2-D barcode reader is used to decodethe digital watermark and/or barcode. The digital watermark (and/orbarcode) includes a related facial recognition hash. If the hashes matchor otherwise coincides the individual and identification document areauthenticated. Or the 2-D barcode reader can be configured to image afingerprint to determine authenticity.

It should be appreciated that while we have referenced “2-D barcodereaders” the present invention is not limited to such. Indeed, asmentioned above, a general purpose computer communicating with animaging device can be used to achieve similar functionality.

Watermarking Identification Card Stock

Another inventive aspect of our present invention is to pre-digitallywatermark identification card stock. For example, before beingpersonalized, identification card stock is digitally watermarked. Thewatermark may be embedded in background print or texturing for example,or in printed fixed information.

To verify authenticity, an identification card must include thepre-embedded digital watermark. This watermark need not include a uniqueidentifier, but rather can include the same identifier per card batch,run or for all cards. (If a batch of cards are misappropriated, cardshaving that batch watermark identifier can be flagged as suspect.).

The digital watermark may even include a so-called fragile watermark. Afragile watermark is designed to destruct or predictably degrade uponsignal processing such as scanning and printing. A fragile watermarkwill help prevent unauthorized copying of the card stock. (Fragiledigital watermarking technology and various applications of such areeven further disclosed, e.g., in assignee's U.S. patent application Ser.Nos. 09/234,780, 09/433,104, 09/498,223, 60/198,138, 09/562,516,09/567,405, 09/625,577, 09/630,243, 09/645,779, 09/689,226, 09/689,289,09/689,293, 60/232,163, 60/247,389, and 09/898,901. Each of theseapplications are herein incorporated by reference.).

Linking Documents through Digital Watermarking

Documents can be linked together, and to a bearer/creator through secureindicia on a photo ID and subsequently issued documents.

Consider the following inventive combination of steps:

-   -   1. Decode a digital watermark identifier embedded within a photo        ID presented by a bearer of the photo ID;    -   2. Embed that watermark identifier or a cryptographic        permutation of the identifier into a first document issued to        the bearer (e.g., a boarding pass, ticket, etc.); and    -   3. Now, the photo ID and first document are linked through the        two digital watermark identifiers. This enables an additional        layer of verification when the bearer presents the photo ID and        first document to gain access, get on a plane, etc. etc. In        particular, the bearer has to present the photo ID and first        document, AND the watermarks extracted from the photo ID and        first document must match or otherwise satisfy a predetermined        relationship, like a cryptographic function.

The two watermarks can be related in many ways. Preferably, thewatermarks are readable by the same detector to simplify deployment. Butto prevent someone from merely copying the watermark from the ID to somefake document, it is useful to alter the watermark in some way thatmaintains the relationship between the two documents but does not yieldthe same watermark.

This concept applies to other forms of printable secure indicia, likesome types of bar codes and scrambled indicia. We can even extend thisto other machine-readable codes, but these codes should be readable fromthe photo ID and then be writable to the document that is issued. Someexamples may include magnetic strip readers and writers, smart cards,etc.

Our inventive system for linking documents in a secure fashion alsoprovides a solution for home printing of say tickets and boarding passes(e.g., a user presents her photo ID at home, the digital watermarkidentifier is extracted from the photo ID and is printed on tickets, theembedded ticket is then verified at the airport gate).

Orientation Signals versus Object or Area Detection

In some digital watermarking techniques, the components of the watermarkstructure may perform the same or different functions. For example, onecomponent may carry a message, while another component may serve toidentify the location or orientation of the watermark in a combinedsignal. This orientation component is helpful in resolving signaldistortion issues such as rotation, scale and translation. (Furtherreference to orientation signals can be made, e.g., to assignee's U.S.patent application Ser. No. 09/503,881, which is herein incorporated byreference.).

We have found that we can forego an orientation signal when embedding adigital watermark message component in an identification cardphotograph, since most identification cards, e.g., a driver's license,include a standard rectangular-shaped photograph. We use objectdetection techniques to locate the photograph shape, determinedistortion based on the expected shape of the photograph area, adjustthe photograph area to compensate for the determined distortion and thendetect the digital watermark from the reshaped (or adjusted) photographarea. We can include even more message bits without significantlyeffecting visibility when we forego an orientation signal.

Once the photograph is realigned we can successfully detect and decode adigital watermark embedded therein. The watermark can be used forauthentication purposes as discussed above.

Perceptual Hashes and Facial Recognition

Another inventive implementation compares a perceptual hash (or facialrecognition data) of a photograph in an identification document with asimilarly computed hash (or data) carried by either a barcode or digitalwatermark. In a detection process, we can use a digital watermarkorientation signal or the object recognition techniques discussed aboveto help realign a distorted captured image of the photograph. Aperceptual hash (or facial recognition analysis) is determined from therealigned photograph. The determined perceptual hash is compared with astored hash recovered from a digital watermark or barcode.

Concluding Remarks

Having described and illustrated the principles of the invention withreference to specific implementations, it will be recognized that theprinciples thereof can be implemented in many other, different, forms.To provide a comprehensive disclosure without unduly lengthening thespecification, applicants incorporate by reference the patents andpatent applications referenced above.

While the above implementations have focused on authenticatingidentification documents, it should be understood that the presentinvention is not so limited. Indeed, digital watermark information canbe compared with information carried by other machine readable codes toauthenticate or compliment product packaging, product labels, producthang tags, receipts, inventory, sale documentation, medical records,credit cards, paper files, software, DVDs, CDs, products, etc., etc.,and any other document or object including a machine readable code anddigital watermark.

The particular combinations of elements and features in theabove-detailed embodiments are exemplary only; the interchanging andsubstitution of these teachings with other teachings in this and theincorporated-by-reference patents/applications are expresslycontemplated.

1. An authentication method comprising: receiving optical scan datacorresponding to a human face; processing the scan data with a facialrecognition module to generate a first hash; receiving optical scan datacorresponding to an identification document including steganographicindicia, wherein the steganographic indicia includes a second hashcorresponding to a facial recognition of the human face; and comparingthe first hash with the second hash to determine whether they coincidein an expected manner.
 2. The method of claim 1, wherein thesteganographic indicia comprises digital watermarking.
 3. The method ofclaim 1, wherein the digital watermarking comprises an orientationcomponent that is helpful to resolve image distortion.
 4. A method toauthenticate an identification document, wherein the identificationdocument comprises a photographic representation of an authorized bearerof the identification document, and wherein said identification documentfurther comprises a digital watermark including first auxiliary data,said method comprising: receiving optical scan data representing atleast a portion of the photographic representation; determining areduced-bit representation of the portion of the photographicrepresentation from the received optical scan data; recovering the firstauxiliary data from the received optical scan data; and comparing thereduced-bit representation of the portion of the photographicrepresentation with the first auxiliary data to authenticate theidentification document.
 5. The method of claim 4, wherein the firstauxiliary data corresponds to a reduced-bit representation of at leastthe portion of the photographic representation.
 6. The method of claim4, wherein the reduced-bit representation comprises facial recognitiondata.
 7. The method of claim 4, wherein the reduced-bit representationcomprises a hash.
 8. The method of claim 4, wherein said digitalwatermark comprises an orientation component.
 9. The method of claim 8,further comprising adjusting the received optical scan data to adjustfor image distortion relative to the orientation component.
 10. Themethod of claim 9, wherein said determining a reduced-bit representationis executed after said adjusting step.
 11. A method to authenticate anidentification document, wherein the identification document comprises aphotographic representation of an authorized bearer of theidentification document, and wherein said identification documentfurther comprises steganographic indicia including first facialrecognition data that corresponds with a human face depicted in thephotographic representation, said method comprising: receiving opticalscan data representing at least a portion of the photographicrepresentation; generating second facial recognition data correspondingto the portion of the photographic representation from the receivedoptical scan data; recovering the first facial recognition data from thereceived optical scan data; and comparing the recovered first facialrecognition data with the second facial recognition data to determinewhether the document is authentic.
 12. The method of claim 11, whereinthe steganographic indicia comprises digital watermarking.
 13. Themethod of claim 12 wherein said digital watermarking comprises anorientation component.
 14. The method of claim 13, further comprisingadjusting the received optical scan data relative to the orientationcomponent.
 15. The method of claim 14, wherein said generating secondfacial recognition data is performed after said adjusting step.
 16. Acomputer readable medium having software instructions stored thereon,said instructions causing a computer to perform the method of claim 4.17. A computer readable medium having software instructions storedthereon, said instructions causing a computer to perform the method ofclaim
 10. 18. A computer readable medium having software instructionsstored thereon, said instructions causing a computer to perform themethod of claim
 11. 19. A computer readable medium having softwareinstructions stored thereon, said instructions causing a computer toperform the method of claim 15.